Oral Surgery Flashcards
Give 7 indications for surgical tooth removal.
- Gross caries (inability to use forceps or elevator)
- Complex root morphology
- Retained roots below alveolar bone
- Impacted teeth
- Displaced teeth
- Ectopic teeth
- Pathology (e.g. cyst)
Define, prevention of complete eruption into a normal functional position due to lack of space or development in an abnormal position.
Impaction
Define, malpositioning of a tooth due to congenital factors, such as a cleft palate.
Ectopic tooth
Define malpositioning for a tooth due to presence of pathology, such as a cyst.
Displaced tooth
Describe a tooth that is “completely unerupted”.
Entirely covered by soft tissue and also partially/totally covered in alveolar bone.
Describe a tooth that is “ankylosed”.
Fused with alveolar bone
At what age do mandibular 3rd molars tend to emerge in the oral cavity?
18-24 years old
In what ratio of adults, do mandibular third molars fail to develop?
1:4
What % of mandibular molars tend to be impacted?
72%
What guidelines should be referred to regarding removal of third molars?
NICE 2000
What % of mandibular third molars are removed as a result of pericoronitis?
8-59%
What is the most common indication for removal of mandibular third molars?
Pericoronitis
Define, inflammation of the tissues around the crown of any partially erupted/impacted tooth.
Pericoronitis
Is one isolated incidence of pericoronitis an indication extract a third molar?
No, one incidence is not a reason to extract as pain is going to happen while tooth erupts. It is when there are 2 or more recurring episodes.
What are the common features of pericoronitis? (Name 7)
- Trismus
- Pain
- Pus under operculum
- Dysphagia
- Malaise
- Bad taste (halitosis)
- Cheek biting and cuspal indentations on the operculum
If patient is systemically well, what is the treatment for pericoronitis?
- Local measures, including:
- Irrigation with warm saline
- OH measures - Removal of trauma e.g. extraction upper 8 or grind down cusps
If a patient is systemically unwell/immunocompromised, what is the treatment for pericoronitis should be considered, but is not a first line option?
Antibiotics
What type of bacteria cause pericoronitis?
Predominantly anaerobic (e.g. strep, Actinomyces etc.)
What two bacteria have been related to the increased incidence of second and third molar periodontal pockets deepening >4-5mm over two years?
- Prevotella intermedia
- Campylobacter rectus
When is it appropriate to prescribe antibiotics to treat pericoronitis?
If there is evidence of systemic spread of infection OR surgical removal of the cause or drainage of the infection under LA is impossible
Why is it that patients might complain of sensitivity on their 2nd molar after removal of their third?
Due to gum recession (usually distally), tooth becomes exposed and more sensitive
What radiographic assessment is best for visualising 3rd molars?
OPG (DPT)
Why are winters lines used in radiographic assessment?
A way of assessing how much bone is likely to be removed in the process of surgery
What are the different classifications of angulation of 3rd molars to adjacent teeth?
- Vertical
- Mesioangular
- Distoangular
- Horizontal
What are 6 radiographic indications of 3rd molar proximity to the IDC canal?
- Narrowing and darkening of canal as nerve crosses root
- Loss of lamina dura of IDC
- Deflection or deviation of IDC
- Dilaceration or deflection of roots as they approach IDC
- Change in colour of roots when crossed by the nerve so that the area appears darker
- Juxta-apical area
What is the most common type of angle of impaction of 3rd molars? (Give % of cases)
Mesialangular impaction (40%)
What is the main consequnece of mesioangular impaction of 3rd molar?
Patient unable to clean between contact points of 3rd and 2nd molar so this becomes a plaque troop and caries can develop on surfaces of both teeth.
What is a juxta-apical area on a DPT?
A well circumscribed radiolucent area lateral to the root rather than at the apex
What are the highest risk radiographic signs of a close relationship of 3rd molar to IDC?
Darkening of roots and juxta-apex
What is the benefit of taking a CBCT image of high risk relationships between the 3rd molar and IDC?
The CBCT will show you exactly where the nerve canal lies in relation to roots as its a 3D image
For the lower lip, what is the short and long term chance of post operative alteration in sensation from extraction of a 3rd molar?
Short term - 5%
Long term- <1%
For the tongue, what is the short and long term chance of post operative alteration in sensation from extraction of a 3rd molar?
Short - 10%
Long - <1%
What is an alternative surgery that can be used if there is high risk of impact to IDN?
Coronectomy
What is a coronectomy?
Where you remove the crown and leave the roots in place
If the roots are mobile at the time of coronectomy, what should be done?
Removal of the roots as they will now be non-vital and could become infected
What is the post-operative 1. risk of infection and 2. Risk of migration, of roots after coronectomy?
2.9% - risk of infection
14-81% - migration
What pre-operative warnings should you give to patients to mandibular third molar surgery?
- Pain
- Swelling
- Bruising
- Possible hypoaesthesia of lip/tongue
- Trismus
- Diet advice
What does hypoaesthesia mean?
Condition where sensation is reduced
What are the long-term probelms that you should warn a patient of if they chose to decline treatment of mandibular 3rd molar?
- Development of further perio probelms
- Caries on 2nd molar and 3rd molar
- Cysts
- External root resorption
- Recurrent pericoronitis
What is the most common application point of an elevator for most teeth?
Mesiobuccaly
What flap design is used for surgical extractions of 3rd Molars?
Triangular flap
What is the difference between a triangular flap and an envelope flap?
There us no mesial relieving incision for an envelope flap
Describe the triangular flap in terms of incisions that need to be made.
- Distal relieving incision (at ascending ramus)
- Peri-coronal incision (cuts through alveolar crest fibres and papilla between 3M and 2M)
- Mesial relieving incision (down from 2M to depth of sulcus)
What rpm should the bur to cut/remove bone be running at?
20,000-40,000rpm
Why is it important to use saline during bone removal?
So that bone doesn’t not overheat under use of bur
Why is bone removed in a surgical extraction?
- To relieve impaction
- To create a point of application for elevator or forceps
If a 3rd molar is horizontally impacted, what must be done as part of surgical extraction?
Crown and root sectioning
What is a major intrinsic obstacle for extraction of a 3rd molar?
Root form, dictates path of withdrawal.
What is the most important suture placed when suturing a flap and why?
The suture placed from the buccal tissues to the lingual tissues immediately distal to the 2nd molar tooth, so to encourage good periodontal health.
What material is used for suturing flaps?
3/0 Vicryl rapide
What post-operative regime should a patient follow after 3rd molar surgery?
- Analgesics
- Hot salt mouthwash
- Soft diet
- Topical ice packs within first 6 hours of treatment
Why does post-operative bleeding tend to occur more in older patients?
This is because the tissues lose their elasticity so you get bleeding into soft tissues spaces.
What are the 5 major complications to 3rd molar surgery that could arise?
- Haemorrhage
- Loose teeth or damage to adjacent teeth/restorations
- Fractured mandible (very rare)
- Dry socket or infection with purulent discharge
- Sensory deficit of tongue or nerves
If maxillary third molars are erupted, how should they be extracted?
Either elevation or forceps extraction
If maxillary third molars are unerupted, how should they be extracted?
By surgical extraction. Raise a buccal flap, remove thin bone with couplins and elevate.
Why should you avoid excess upwards forces when elevating a maxillary 3rd molar?
Due to possible displacement of tooth into antrum
What is the second most commonly impacted tooth, after 3rd molars?
Maxillary canines
What is the prevalence of impacted maxillary canines?
1.7%
Are ectopic maxillary canines more likely to be found palatally or buccaly?
Palatally
At what age are maxillary canines normally palpable in the labial sulcus?
10-11 years old
What is thought to act as a guidance plane in the path of eruption for a maxillary canine?
The distal aspect of the lateral incisor
Clinically, how would you identify impacted maxillary canines? give 5 signs.
- Canines can be palpated in the sulcus or palate age 12/13+ (late)
- Evidence of rotation/tilting of adjacent teeth
- Mobility/sensibility of adjacent teeth
- More than 6 months since contralateral tooth has erupted
- Presence of deciduous canine after expected age of exfoliation
Radiographically, how would you investigate impacted canines?
Parallax films:
1. Periapical x2
2. Occlusal
3. DPT
CBCT (In select cases)
What are the two treatment options for dilacerated, impacted teeth?
- Do nothing and monitor
- Surgical extraction
Can unerupted, dilacerated teeth be orthodontically aligned?
No
What can be sequelae of canine impaction, where a conservative treatment option is chosen?
- Resorption of incisor roots
- Cystic change
- Infection of cyst close to surface mucosa may lead to sinus tract formation
What are the 5 treatment options for impacted canines?
- Conservative
- Interceptive
- Exposure
- Surgical removal
- Auto-transplantation
What treatment option would be most appropriate in the case of impacted maxillary canines where…
- patient is unwilling to have orthodontic treatment
- patient is happy with appearance and has healthy adjacent teeth.
- radiographs show absence of pathology or resorption
Conservative treatment where the tooth is monitored over time
What treatment option would be most appropriate in the case of impacted maxillary canines where…
- patient is young (10-13 years old)
- minimal crowding of teeth and space can be maintained
Interceptive treatment, where the deciduous tooth is extracted in the hope that the permanent impacted tooth will have space to erupt.
What treatment option would be most appropriate in the case of impacted maxillary canines where…
- well motivated patient who is willing to have orthodontic treatment
- pt with good oral hygiene
- impacted canine is not grossly displaced
Exposure and alignment of impacted tooth
Describe the “open technique” for exposure and alignment of an impacted tooth. what is the disadvantage of this technique?
Apically repositioned flap or palatal window, where tissue overlying tooth is removed and the gingiva is sutured at a higher position than originally placed to encourage eruption.
Disadvantage = aesthetics can be poor, risk of exposure of canine roots upon erupting
Describe the “closed technique” for exposure and alignment of an impacted tooth. what is the advantage of this technique?
Where an orthodontic bracket and gold chain is attached to impacted tooth to allow orthodontic traction.
Advantage = mimics physiological eruption of canine, which means the impacted canine will erupt through attached gingiva and therefore give a good gingival contour.
What treatment option would be most appropriate in the case of impacted maxillary canines where…
- patient is non-compliant
- patient finds appearance satisfactory with C
- advanced resorption of incisors
- malpositioned canine with difficult root morphology
Surgical removal of canine (and any other teeth with extensive root resorption)
What is the technique for surgical removal of an impacted maxillary canine?
- Usually palatal envelope flap made (can be buccal)
- Removal of overlying bone to maximum convexity of tooth (sectioning may be required if root morphology complex)
- Elevation of maxillary canine
If surgically removing bilateral maxillary canines, what is required during the procedure in order to cut the flap, that can only be justified for this specific procedure?
Severing contents of the incisive foramen (neurovascular bundle)
When using surgical instruments, what should always be used in conjunction? And why?
Saline irrigation, to prevent bone from overheating.
What is the failure rate of an auto-transplanted tooth?
Failure rate of 30% (high)
On plain film, what are the three most significant radiographic signs of a close relationship between the 3rd molar and the inferior dental canal?
- Diversion of IAN canal
- Darkening of the root
- Interruption of the cortical white line
What management method of M3Ms is effective in minimising inferior alveolar nerve injury upon this tooth’s removal?
Coronectomy
What bacteria species have been related to the increased incidence of second and third molar periodontal pockets deepening (>4-5mm) over two years?
Prevotella intermedia and campylobacter rectus
Define, exaggerated sensation to touch, or cold or warm stimuli.
Hyperaesthesia
What is the most common complication after third molar surgery?
Dry socket (alveolar osteitis)
When might prophylactic removal of teeth (including M3Ms) be indicated for medical procedures? Give two examples.
Prior to organ transplantation or chemotherapy
What is the optimal post-operative pain management for dental extractions in adults?
Ibuprofen (400mg) + paracetemol (1000mg)
What are the two main risk factors for displacement of molar roots into the maxillary antrum?
- Age over 40 years
- Lone standing molars with ridge resorption and protrusion of molar roots into the antrum.
What is the key criteria for coronectomy?
- High risk of IAN injury
- Vital M3M
- Healthy non-immunocompromised patient
What are the potential complications of coronectomy?
- Mobilisation of roots intra operatively
- Early recurrent dry socket and need for removal of roots following coronectomy
- Late eruption and possible infection of retained roots
- Injury to the lingual nerve and IAN
What is the main risk from ectopically placed canines?
Root resorption of adjacent teeth
When should a dental practitioner suspect that a canine is ectopic?
If it is not palpable in the buccal sulcus by the age of 10-11 years old
What is meant by parallax?
The apparent displacement of an object because of different positions of an observer
What age of patient should you start to annually attempt to palpate the canine region?
8 years old
What tooth is the 3rd most commonly impacted tooth in the mouth?
Maxillary incisors
What signs of delayed eruption would indicate investigation of maxillary incisors?
- If contralateral teeth erupted 6/12 months previously or in the case when both upper centrals missing one year after eruption of lower incisors
- Deviation from normal sequence of eruption, i.e. laterals erupt before centrals
What is the most common hereditary cause of impacted maxillary incisors?
Presence of supernumerary tooth
List the hereditary causes of an impacted maxillary incisor? (7)
- Supernumeraries
- Cleft lip/palate
- Cleidocranial dysostosis
- Odontomes
- Abnormal tooth/tissue ratio
- Gingival fibromatosis
- Generalised retarded eruption
List the environmental causes of an impacted maxillary incisor? (6)
- Trauma or root dilaceration
- Early loss or extraction of deciduous tooth
- Retained deciduous tooth
- Cyst formation
- Endocrine abnormalities
- Bone disease
What management options are most commonly carried out for impacted maxillary incisors?
Exposure or Interceptive treatment
What is the 4th most likely impacted tooth in the mouth?
Mandibular premolars
What is the main cause of impacted mandibular premolars?
Crowding
What sort of flap is cut for surgical extraction of mandibular premolars?
2 sided flap (coronal and mesial relieving incisions)
What condition is hyperdontia associated with?
Cleidocranial dysostosis
What are the two types of Odontomes?
Complex or compound
How are complex Odontomes formed?
By invaginations of tooth germ or a genetic malformation called a hamartoma
What % of all odontogenic tumours do complex Odontomes account for?
22%
What causes compound Odontomes to form?
Exuberant proliferation of dental lamina
What Odontomes are most commonly found…
1. Anteriorly
2. Posteriorly
- Compound
- Complex
Define “dilaceration”
An acute deviation of the long axis of the tooth, located to the crown or root
In a younger patient (<9 years old) with an impacted immature permanent maxillary incisor, what is the best initial management?
Allow up to 9-12 months for the spontaneous eruption of the incisor after the removal of an obstruction (e.g. decidious tooth)
In an older individual (>9 years old) with an impacted immature permanent maxillary incisor, what is the best initial management?
Consider surgical exposure with bonding of orthodontic bracket attachement at the time of removal of any obstruction.
What is another name for maxillary sinus?
Sinus of highmore
What are the 4 bilateral paranasal sinuses?
- Frontal
- Ethmoid
- Sphenoid
- Maxillary
What structure do sinuses drain through?
An osteum
Where does the maxillary sinus drain into?
The middle meatus